Which of the following is a small star that has reached the end of its stellar evolution?
neutron star
red giant
stellar nebula
white dwarf

Aneutron and a proton combine to form a nucleus. why does the mass of the nucleus differ from the sum of the masses of the individual nucleons?

In one or two sentences, describe how you did in the balancing game. in a few more sentences, explain one strategy you learned for balancing more complex equations.

Which planet do you think would be easiest for humans to colonize some day?